Resin film, coverlay for printed wiring board, substrate for printed wiring board, and printed wiring board

Abstract

A resin film containing a fluororesin as a main component has, on at least one surface thereof, a pre-treated surface having a content ratio of oxygen atoms or nitrogen atoms of 0.2 atomic percent or more. A coverlay includes the resin film and an adhesive layer laminated on the pre-treated surface. A substrate for a printed wiring board includes the resin film and a conductive layer laminated on the pre-treated surface. A printed wiring board includes an insulating base layer, a conductive pattern laminated on at least one surface of the base layer, and the coverlay for a printed wiring board, the coverlay being laminated on the conductive pattern.

1 : A resin film comprising a fluororesin as a main component,
 wherein the resin film has, on at least one surface thereof, a pre-treated surface having a content ratio of oxygen atoms or nitrogen atoms of 0.2 atomic percent or more.   
     
     
         2 : The resin film according to  claim 1 , wherein a contact angle of the pre-treated surface with respect to pure water is 90° or less. 
     
     
         3 : The resin film according to  claim 1 , wherein a peel strength of an epoxy resin adhesive having an average thickness of 25 μm to the pre-treated surface, the peel strength being measured using a polyimide sheet having an average thickness of 12.5 μm as a flexible adherend, is 1 N/cm or more. 
     
     
         4 : A coverlay for a printed wiring board, the coverlay comprising the resin film according to  claim 1 ; and an adhesive layer laminated on the pre-treated surface. 
     
     
         5 : The coverlay for a printed wiring board according to  claim 4 , wherein a peel strength between the adhesive layer and the pre-treated surface is 1 N/cm or more. 
     
     
         6 : A substrate for a printed wiring board, the substrate comprising the resin film according to  claim 1 ; and a conductive layer laminated on the pre-treated surface. 
     
     
         7 : The substrate for a printed wiring board according to  claim 6 , wherein a peel strength between the pre-treated surface and the conductive layer is 1 N/cm or more. 
     
     
         8 : A printed wiring board comprising:
 an insulating base layer;   a conductive pattern laminated on at least one surface of the base layer; and   the coverlay for a printed wiring board according to  claim 4 , the coverlay being laminated on the conductive pattern.   
     
     
         9 : A printed wiring board comprising the resin film according to  claim 1 ; and a conductive pattern laminated on the pre-treated surface. 
     
     
         10 : A printed wiring board comprising the resin film according to  claim 1 ; and a conductive pattern laminated on a surface of the resin film,
 wherein the pre-treated surface is disposed in a conductive pattern-non-laminated region on the surface of the resin film.   
     
     
         11 : The printed wiring board according to  claim 10 , wherein the pre-treated surface is disposed in a conductive pattern-laminated region.